BABIES

A  child  grows  faster  during  babyhood  than  at  any  other  stage  of  its  life,  including
adolescence. By the age of 18 months a girl is usually half her adult height, and a boy is by the
age of two years. 
There  is  little correlation between  the rate of growth  in childhood and eventual height. Many
children grow quickly and then stop early so that they are short, whereas others seem to grow at
a slower pace but continue until they outstrip everyone else. 
The most significant  factor  in determining height  is heredity  -  the children of  tall parents will


usually also be tall. Nutrition is also significant, and a child who is poorly nourished is likely to be
shorter than one who is well nourished. Advances in nutrition are the main reason for an overall
increase in the height of populations of the developed world. 
Body proportions of babies and children are markedly different from those in adults. A baby's
head  is  disproportionately  large  compared  with  that  of  an  adult,  and  its  legs  are
disproportionately short. A baby's head  is about a quarter of  its  length, but an adult's head  is
about  one  eighth  of  their  height.  Between  birth  and  adulthood,  a  person's  head  just  about
doubles in size, the trunk trebles in length, the arms increase their length by four times, and the
legs grow to about five times their original length. 
At birth, babies have almost no ability  to control  their movements. At  the age of about  four
weeks, a baby placed on  its stomach can usually hold  its head up. At about  four months,  the
baby will usually be able to sit up with support, and at the age of seven months should be able
to sit alone. At around eight months, most babies can stand with assistance, and will start  to
crawl at  ten months. They can probably put one  leg after  the other  if  they are  led at about 11
months, and pull  themselves up on  the  furniture by one year. At about 14 months a baby can
usually stand alone, and the major milestone of walking will probably occur around 15 months. 
These are average figures and many children will reach them much earlier and others much
later. Physical development does not equate with mental development, and parents should not
be concerned  if  their child  takes  its  time about  reaching  the various stages  - Einstein was so
slow in learning to talk that his parents feared he was retarded.
Most newborn babies sleep most of  the  time - although  there are wide variations and some
babies seem  to stay awake most of  the day and night,  to  the distress of  their parents. As  they
grow, a baby's need  for sleep diminishes until a  toddler  requires about  ten or  twelve hours of
sleep a night, with a nap in the daytime.